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seqlock: rename write_lock/unlock to write_begin/end

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It is a more appropriate name, now that the mutex embedded
in the seqlock is gone.

Reviewed-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1465412133-3029-4-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Emilio G. Cota 2016-06-08 14:55:21 -04:00 committed by Richard Henderson
parent ccdb3c1fc8
commit 03719e44b6
2 changed files with 16 additions and 16 deletions
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28
cpus.c
View File

@ -249,13 +249,13 @@ int64_t cpu_get_clock(void)
void cpu_enable_ticks(void) void cpu_enable_ticks(void)
{ {
/* Here, the really thing protected by seqlock is cpu_clock_offset. */ /* Here, the really thing protected by seqlock is cpu_clock_offset. */
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
if (!timers_state.cpu_ticks_enabled) { if (!timers_state.cpu_ticks_enabled) {
timers_state.cpu_ticks_offset -= cpu_get_host_ticks(); timers_state.cpu_ticks_offset -= cpu_get_host_ticks();
timers_state.cpu_clock_offset -= get_clock(); timers_state.cpu_clock_offset -= get_clock();
timers_state.cpu_ticks_enabled = 1; timers_state.cpu_ticks_enabled = 1;
} }
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
} }
/* disable cpu_get_ticks() : the clock is stopped. You must not call /* disable cpu_get_ticks() : the clock is stopped. You must not call
@ -265,13 +265,13 @@ void cpu_enable_ticks(void)
void cpu_disable_ticks(void) void cpu_disable_ticks(void)
{ {
/* Here, the really thing protected by seqlock is cpu_clock_offset. */ /* Here, the really thing protected by seqlock is cpu_clock_offset. */
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
if (timers_state.cpu_ticks_enabled) { if (timers_state.cpu_ticks_enabled) {
timers_state.cpu_ticks_offset += cpu_get_host_ticks(); timers_state.cpu_ticks_offset += cpu_get_host_ticks();
timers_state.cpu_clock_offset = cpu_get_clock_locked(); timers_state.cpu_clock_offset = cpu_get_clock_locked();
timers_state.cpu_ticks_enabled = 0; timers_state.cpu_ticks_enabled = 0;
} }
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
} }
/* Correlation between real and virtual time is always going to be /* Correlation between real and virtual time is always going to be
@ -294,7 +294,7 @@ static void icount_adjust(void)
return; return;
} }
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
cur_time = cpu_get_clock_locked(); cur_time = cpu_get_clock_locked();
cur_icount = cpu_get_icount_locked(); cur_icount = cpu_get_icount_locked();
@ -315,7 +315,7 @@ static void icount_adjust(void)
last_delta = delta; last_delta = delta;
timers_state.qemu_icount_bias = cur_icount timers_state.qemu_icount_bias = cur_icount
- (timers_state.qemu_icount << icount_time_shift); - (timers_state.qemu_icount << icount_time_shift);
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
} }
static void icount_adjust_rt(void *opaque) static void icount_adjust_rt(void *opaque)
@ -355,7 +355,7 @@ static void icount_warp_rt(void)
return; return;
} }
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
if (runstate_is_running()) { if (runstate_is_running()) {
int64_t clock = REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT, int64_t clock = REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT,
cpu_get_clock_locked()); cpu_get_clock_locked());
@ -374,7 +374,7 @@ static void icount_warp_rt(void)
timers_state.qemu_icount_bias += warp_delta; timers_state.qemu_icount_bias += warp_delta;
} }
vm_clock_warp_start = -1; vm_clock_warp_start = -1;
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
if (qemu_clock_expired(QEMU_CLOCK_VIRTUAL)) { if (qemu_clock_expired(QEMU_CLOCK_VIRTUAL)) {
qemu_clock_notify(QEMU_CLOCK_VIRTUAL); qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
@ -399,9 +399,9 @@ void qtest_clock_warp(int64_t dest)
int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
int64_t warp = qemu_soonest_timeout(dest - clock, deadline); int64_t warp = qemu_soonest_timeout(dest - clock, deadline);
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
timers_state.qemu_icount_bias += warp; timers_state.qemu_icount_bias += warp;
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL); qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL);
timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]); timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]);
@ -468,9 +468,9 @@ void qemu_start_warp_timer(void)
* It is useful when we want a deterministic execution time, * It is useful when we want a deterministic execution time,
* isolated from host latencies. * isolated from host latencies.
*/ */
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
timers_state.qemu_icount_bias += deadline; timers_state.qemu_icount_bias += deadline;
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
qemu_clock_notify(QEMU_CLOCK_VIRTUAL); qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
} else { } else {
/* /*
@ -481,11 +481,11 @@ void qemu_start_warp_timer(void)
* you will not be sending network packets continuously instead of * you will not be sending network packets continuously instead of
* every 100ms. * every 100ms.
*/ */
seqlock_write_lock(&timers_state.vm_clock_seqlock); seqlock_write_begin(&timers_state.vm_clock_seqlock);
if (vm_clock_warp_start == -1 || vm_clock_warp_start > clock) { if (vm_clock_warp_start == -1 || vm_clock_warp_start > clock) {
vm_clock_warp_start = clock; vm_clock_warp_start = clock;
} }
seqlock_write_unlock(&timers_state.vm_clock_seqlock); seqlock_write_end(&timers_state.vm_clock_seqlock);
timer_mod_anticipate(icount_warp_timer, clock + deadline); timer_mod_anticipate(icount_warp_timer, clock + deadline);
} }
} else if (deadline == 0) { } else if (deadline == 0) {

4
include/qemu/seqlock.h
View File

@ -28,7 +28,7 @@ static inline void seqlock_init(QemuSeqLock *sl)
} }
/* Lock out other writers and update the count. */ /* Lock out other writers and update the count. */
static inline void seqlock_write_lock(QemuSeqLock *sl) static inline void seqlock_write_begin(QemuSeqLock *sl)
{ {
++sl->sequence; ++sl->sequence;
@ -36,7 +36,7 @@ static inline void seqlock_write_lock(QemuSeqLock *sl)
smp_wmb(); smp_wmb();
} }
static inline void seqlock_write_unlock(QemuSeqLock *sl) static inline void seqlock_write_end(QemuSeqLock *sl)
{ {
/* Write other fields before finalizing sequence. */ /* Write other fields before finalizing sequence. */
smp_wmb(); smp_wmb();